Suspension arrangement

ABSTRACT

In a McPherson strut suspension, the top end of the strut 26 is not positively secured against axial movement in its seat 28 but is prevented from moving from its seat on full extension by abutment of a bracket 44 fixed to the strut with a stop 46 fixed to the chassis.

FIELD OF THE INVENTION

This invention relates to a suspension arrangement which includes aMcPherson strut. McPherson struts are widely used in motor vehiclesuspensions.

DESCRIPTION OF THE PRIOR ART

FIG. 1 shows one standard McPherson strut arrangement where the top endof the strut 2 is received in a seat 4 in the vehicle chassis (usuallypart of the vehicle bodywork 6). Under normal operating conditions, theweight of the vehicle bodywork is sufficient to ensure that the top endof the strut remains properly positioned in its seat. However at fullyextended or `full hang` positions, there is a possibilty that the topend of the strut may fall out of its seat, and to prevent this happeningor to guide the top end of the strut back into its seat when normaloperation is resumed, a retaining plate 8 is mounted on the inside ofthe bodywork and connected to the top end of the strut on the axis ofthe strut. This axially mounted retaining plate prevents the strut frombecoming separated from its seat. However the use of a retaining plateof this nature requires access to the inside of the vehicle duringassembly to secure a nut 9, and this is disadvantageous.

SUMMARY OF THE INVENTION

According to the invention, there is provided a suspension arrangementwhich includes a McPherson strut, wherein the top end of the strut islocated from below in a seat in the vehicle chassis, is normallyretained in its seat by the weight of the vehicle bodywork, and whereinthe strut has a radial projection arranged so that the projection willcome into contact with part of the chassis when the strut extends, todefine the maximum strut extension, before the top end of the strut isdisplaced from its seat.

A suspension arrangement of this type has particular advantages duringassembly of the vehicle because the suspension can be fitted to thevehicle body operating only from beneath the body. It is not necessaryfor any operations to take place inside the body.

In one embodiment, the top end of the strut is not anchored to thevehicle bodywork, i.e. no fasteners are used to hold the top end of thestrut to the bodywork. When the radial projection contacts the chassispart, a twisting torque will be developed on the strut and this willtend to move the top of the strut sideways. This torque can be resistedby locating the top of the strut within a socket in the underside of thebodywork. Alternatively or additionally, the twisting torque can beresisted by a flange screwed to the underside of the bodywork. It isalso possible for the top end of the strut to be held to the bodywork bya frictional engagement produced when the top end of the strut isintroduced into a socket from below the vehicle.

For the purposes of this specification, the vehicle chassis includes thevehicle body panels, in particular the body panels to which thesuspension components are secured.

The radial projection is preferably angled downwards away from thestrut, and the chassis part preferably has a corresponding upwardinclination so that when the projection and the cassis part meet, theyinterlock to a certain extent.

The part of the chassis may be a part of a body cross member which isextended into the path of the radial projection.

Either the radial projection or the part of the chassis may carry ashock-absorbing pad such as a rubber pad.

Preferably the part of the chassis is part of a chassis cross member towhich the suspension arms are attached, so that an entire axle assemblyconsisting of the wheel knuckles, the suspension struts, suspension armsand vehicle cross member can ben pre-assembled and entirely connected tothe vehicle simply by securing the cross member to side rails of thechassis.

The invention thus provides a simple way of retaining the top end of thestrut without attaching anything to the strut from inside the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described, by way of example, withreference to the accompanying drawings, in which;

FIG. 1 is a side elevation of a suspension arrangement in accordancewith the prior art;

FIG. 2 is a view corresponding to FIG. 1 but showing a suspensionarrangement in accordance with the invention;

FIG. 3 is a plan view of the arrangement of FIG. 2 taken on the line;

FIG. 4 is a perspective view of the projection on the strut; and

FIG. 5 is a side view of the projection in contact with the chassismember.

DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 2 shows part of the bodywork 20 of a vehicle with a lower side rail22. There will be a corresponding side rail on the opposite side of thevehicle but this is not shown in the figures. The vehicle bodywork formsa tower 24 into which the top end of the strut 26 extends. At the top ofthe tower there is a seat 28, and the top end of the strut sits in thisseat. Normally the weight of the vehicle bodywork acts downwardly onthis seat and loads the strut so that the strut remains located in theseat.

At the bottom end of the strut there is a wheel knuckle 30 with aspindle 32, and the centreline of a wheel to be mounted on the spindleis indicated by the line 34. The knuckle 30 is also connected to avehicle cross member 36 by two suspension arms 38 and 40. The crossmember 36 supports the inner ends of the suspension arms 38, 40 and issecured to the side rail 22 by bolts 42.

The lower part of the strut 26 has a welded-on bracket 44 (see FIGS. 4and 5) which extends radially outwardly from the axis of the strut. Asthe strut extends and retracts, so the bracket 44 moves up and downrelative to the bodywork 20. Located in the path of movement of thebracket 44, at the lower end of the possible travel of the bracket, is astop 46 formed by an outward extension of the cross member 36. The stop46 carries a rubber bumper 48, and it will be seen that when the bracket44 makes contact with the bumper 48 on the stop 46 the limit of srutextension is reached. Further extension of the strut will be impossiblebecause the strut will be constrained between the seat 28 and the stop46 which are both fixed in relation to one another. The stop 46 can beeasily formed by a small extension of the material of the cross member36 which itself is formed by a metal pressing.

If the bracket 44 does come into contact with the stop 46, a twistingtorque will be exerted on the top of the strut 26, tending to move thestrut sideways in the socket 28. This torque is resisted by a component58 which is moulded into the rubber top mount of the strut and has aradial flange 60. The flange 60 is bolted to the vehicle body fromunderneath, the bolt 62 being secured in a weld nut 64. This flange isonly loaded in its own plane by forces acting in a direction generallyat right angles to the strut axis. It is only possible to gain access tothe area of the tower 24 at one side of the strut, and so bolts 62 canonly be fastened on one side. The component 58 does not therefore play apart in resisting axial movement of the strut out of the socket 28; thismovement is resisted by the bracket 44 and stop 46.

The bracket 44 is stamped and folded from sheet metal and is shown inmore detail in FIGS. 4 and 5. It has side walls 50, top flanges 52 and abase 54 to provide strength, and the parts of the bracket which makecontact with the outer walls of the strut tube are welded to the tube.An inner reinforcement 56 is welded within the walls 50 and the base 54.

In this way, the strut can be secured in the vehicle with its top mountsimply push-fitted into the top of the tower 24. Normally the weight ofthe vehicle will ensure that the strut remains in the seat 28, but atmaximum suspension rebound, the strut will still be slightly compressedbetween the seat 28 and the stop 46, and this compression will besufficient to retain the top of the strut in-the seat.

It is a distinct advantage for assembly, particularly automatedassembly, that no operator or tools need be taken inside the car tosecure the suspension top mount.

I claim:
 1. A suspension arrangement for use in a vehicle having achassis which includes a McPherson Strut and a suspension arm, whereinthe top end of the strut is located from below in a seat in the chassisand is normally retained in its seat by the weight of the vehicle,characterized in that the strut has a radial projection arranged so thatthe projection will come into contact with part of the chassis when thestrut extends, to define the maximum strut extension, before the top endof the strut is displaced from its seat.
 2. A suspension arrangement asclaimed in claim 1, characterised in that the part of the chassis is apart of a body cross member which is extended into the path of theradial projection.
 3. A suspension arrangement as claimed in claim 1characterised in that no fasteners are used to hold the top end of thestrut to the bodywork.
 4. A suspension arrangement as claimed in claim3, characterised in that twisting torque developed on the strut isresisted by locating the top of the strut within a socket in theunderside of the bodywork.
 5. A suspension arrangement as claimed inclaim 3, characterised in that twisting torque is resisted by a platescrewed to the underside of the bodywork.
 6. A suspension arrangement asclaimed in claim 3, characterised in that top end of the strut is heldto the bodywork by a frictional engagement produced when the top end ofthe strut is introduced into a socket from below the vehicle.
 7. Asuspension arrangement as claimed in claim 1, characterized in that theradial projection comprises a rubber pad.
 8. A suspension arrangement asclaimed in claim 1, characterised in that the cooperating faces of theradial projection and the part of the chassis are parallel and inclinedto the axis of the strut.
 9. A suspension arrangement as claimed inclaim 1, characterised in that the part of the chassis is part of achassis cross member to which the suspension arm attaches.
 10. Asuspension arrangement for use in a vehicle having a chassis, saidsuspension arrangement comprising:a knuckle; a suspension arm pivotallyinterposed between the chassis and said knuckle; a seat in the chassis;a McPherson strut wherein a top end of said strut is inserted from belowthe chassis into said seat and is normally retained in said seat by theweight of the vehicle and a bottom end attached to said knuckle; a stopdisposed on the chassis; a bracket disposed on said strut, said bracketbeing adapted to contact said stop thereby defining the maximum strutextension to prevent said top end of said strut from displacing fromsaid seat; and a plate secured within said seat by a single fastener,said plate having a socket therein to resist twisting torque developedon said strut when said bracket engages said stop.
 11. A suspensionarrangement as claimed in claim 10, wherein cooperating faces of saidbracket and said stop are parallel and inclined to the axis of thestrut.